Self sealing pierceable stopper for sealed containers



June 9, 1964 A. E. KRUG ETAL 3,136,440

SELF SEALING PIERCEABLE STOPPER FOR SEALED CONTAINERS Filed June 25, 1963 INVENTORS. 4155,?! 5. l/IPUG 660/4 6! M K5440? III'TOIP/VEYJ United States Patent 3,136,440 SELF SEALING PIERCEABLE STOPPER FOR SEALED CONTAINERS Albert E. Krug, Wyclkolf, and George H. Keller, Ridgewood, N.J., assignors to Becton Dickinson and Company, East Rutherford, NJL, a corporation of New Jersey Filed June 25, 1963, Ser. No. 290,899 1 @laim. (Cl. 215-47) This invention relates to an improved self sealing pierceable stopper for sealed containers.

In the medical, biological and laboratory fields, sealed containers are frequently provided with pierceable self sealing stoppers whereby entry can be made into the container by means of a hypodermic needle so that fluids can be inserted in and removed from the container without breaking the sterility of the container. After the needle is removed from the stopper it immediately reseals. One type of stopper used'for this purpose is made of elastomeric material and is provided with a cylindrical plug portion, an enlarged head portion and a pierceable diaphragm extending across the stopper. Stoppers of this type have frequently been used with evacuated tubes and containers used in the collection of blood. This type of stopper has served very satisfactorily to provide the desired seal and to permit the insertion and removal of fluids. However, from time to time, difficulty has been encountered with the stopper in that it automatically escaped or ejected from the container breaking the sterility and causing contamination or loss of the contents.

It is a prime object of the present invention to provide an improved pierceable self sealing stopper of the above type which may be readily inserted in and removed from the opening in a container but which when inserted in the opening will remain firmly seated in place without danger of accidental release orejection.

Further objects include the provision of an improved pierceable self sealing stopper of the above type which is of relatively simple and inexpensive construction; which may be readily applied to and removed from a container and used in the same manner as stoppers of this type heretofore available; and which serves to preserve the seal and sterility of the container to which it is applied while permitting the insertion and removal of fluids by means of a hypodermic needle.

Our invention contemplates the provision of a self sealing pierceable stopper having a body portion made of elastomeric material and having a plug portion for inserting in the opening in the container and an enlarged head portion for engaging the outer end of the container. Around the plug portion immediately adjacent the enlarged head portion we provide a circumferential groove so as to relieve the stresses resulting from the resistance of the head portion to the compression of the plug. In accordance with a further aspect of our invention, recesses are provided at the opposite end of the stopper and the upper surface of the diaphragm is concave and the lower surface is convex thus directing the flow of the diaphragm material inwardly when the plug is compressed in insertion in the opening of a container.

In the accompanying drawing:

FIG. 1 is a side elevational view partially in section of a blood collecting assembly having a stopper embodying our invention applied to an evacuated tube or container;

FIG. 2 is an enlarged detailed view in section of the upper end of the container with the stopper applied thereto;

FIG. 3 is an exploded view in perspective of the stopper and the upper portion of the container; and

I by the fluids with which it is used. For this purpose we 3,136,440 Patented June 9, 1964 "ice FIG. 4 is a partially sectional side elevational view of the plug.

Our improved stopper is shown generally at 5. In FIGS. 1 and 2 it is illustrated as applied to the open upper end of a tubular container 6 which is closed at its lower end. The assembly illustrated is of the type frequently used in collecting blood specimens and the stopper has sealing engagement with the container and said container is at least partially evacuated so that blood will be drawn into the container when a cannula having connection with a bloodvessel is inserted therethrough.

Container 6 is preferably made of glass, but it may be made of a suitable plastic material inert to. and unaffected by the fluids to be collected therein. Assembled with the container and stopper in FIG. 1 is a holder 7 open at its lower end and of a size to have sliding fit with the container as shown. The holder 20 has a tapered top portion 8 formed with an aperture therethrough with which the hub-like fitting 9 has sealing engagement. A double ended cannula is mounted in sealing relationship with the hub-like fitting 9 with one end projecting into the holder and the other end projecting outwardly therefrom. In using the device illustrated in FIG. 1, the outwardly projecting portion of the cannula may be inserted into a blood vessel and then the inwardly projecting portion of the cannula is projected through the stopper with the result that blood is drawn into the sealed, evacuated container, 6. When the desired quantity .of blood has been drawn into the container, the cannula, in normal practice, is withdrawn from the stopper and then from the blood vessel. Upon withdrawal of the cannula from the stopper, it automatically reseals itself. It should be understood that the container maybe sterilized before its use in this fashion and that it may contain various blood treathave found that natural or synthetic rubber serves quite satisfactorily. Various elastomeric plastic compositions having the above indicated characteristics may also be employed under certain circumstances as, for instance,

the polymers and copolymers of vinylchloride or'vinyldienechloride.

The body portion of the stopper comprises a plug 10 having an enlarged head portion 12 integrally connected to the upper end thereof. The outside diameter of the plug 10 is slightly larger than the inside diameter of the opening in the container to which it is applied. Thus, when the plug is inserted into the open end of the container as shown in FIGS. 1 and 2, it is partially compressed. This helps to insure sealing engagement with the container as well as self sealing of the stopper when a cannula which has been inserted therethrough is withdrawn therefrom. The diameter of the head portion should be large enough to overlap the open upper end of the container as shown in FIGS. 1 and 2 so that it can be pressed into engagement therewith when the stopper is applied to the container. Recesses 14 and 16 are formed in the upper head end of the stopper and in the lower plug end of the stopper as shown. Extending across the stopper so as to overlap the area of connection between the head and plug portions is a diaphragm 18 also formed integrally with the remainder of the stopper. The diaphragm provides a partition or separation between the recesses 14 and 16 through which the cannula may be inserted when it is desired to add or remove fluid from the container. The upper surface of the diaphragm is preferably concave as shown at 20 and the lower surface is preferably convex as shown at 22. Thus, when the plug is compressed, the flow of the elastomeric material in the diaphragm is directed inwardly thereby minimizing stresses which might tend to eject or force the stopper outwardly from the container.

Around the outer surface of the plug, immediately adjacent the head 12, we provide a circumferential groove 24 which servesto minimize or relieve the stresses adjacent this portion of the plug resulting from the resistance of the head of the stopper to compression of the plug when it is inserted in the opening in the container. Thus, stresses in this area of the plug which tend to eject the stopper from the container are minimized or eliminated.

In order to facilitate the insertion of the plug end of the stopper into the opening of the container, we preferably taper the outer surface of the plug inwardly toward the free end thereof, as shown at 2 6. I

In using our improved stopper, it is applied to a container having an opening whose inside diameter is slightly less than the outside diameter of the plug portion. The plug is inserted in the opening as shown in FIGS. 1 and 2 with the head overlapping and pressed against the outer end of the container. Thus, the stopper provides a seal for the open end of the container; The container may be evacuated by inserting a hypodermic needle through the diaphragm 18 and drawing a vacuum therethrough or by inserting the stopper in the containers while in anevacuated chamber. When the needle is then withdrawn, the diaphragm is then self sealing. If the container is to be used for the collection of blood, blood drawing and preserving materials may be inserted therein. The sealed container may be sterilized in an autoclave in the usual manner. Liquids may be introduced into and withdrawn from the container by means of a hypodermic needle inserted through the diaphragm. In the collection of blood samples, the assembled container and stopper may be used with a holder of the type shovm at 7 in the manner described at the beginning of this specification.

When the stopper is assembled with the container in the manner illustrated and described, the plug 1G is partially compressed and the frictional engagement between the plug and container serves to hold the stopper in place against accidental displacement. Stresses and forces which might tend to eject the stopper from the container are relieved and minimized due to the provision of the circumferential groove 24 immediately adjacent the head and due to the concave-convex configuration of the diaphragm which directs the flow of elastomeric material inwardly when the plug is compressed; It will be seen .Cil

, 4 7, that the stopper is designed so that the maximum amount of rubber is disposed down inside the tube or container to firmly seal it in place.

Thus, we have provided an improved self sealing pierceable stopper for sealed containers which may be readily applied to containers but which will be firmly retained in place while the stopper is in use. It will also be seen that the stopper is of relatively simple and inexpensive construction and that it can be readily utilized'in the manner of self sealing pierceable stoppers heretofore available so as to provide sealing engagement with the container and at the same time permitting the insertion and removal of materials into and from the container without breaking the seal.

Modifications may be made in the illustrated and described embodiment of our invention without departing from the invention as set forth in the accompanying claim.

We claim:

A self sealing pierceable stopper for sealing containers of'the type having a tubular top with an opening therethrough which comprises: a body made of elastomeric material and comprising a cylindrical plug and an enlarged flange like head at the upper end thereof, said head and plug having recesses entering from the ends thereof with a diaphragm at the intermediate portion integral with said body and separating said recesses and connected across the upper portion of the plug and the lower portion of the head, said diaphragm having a concave'upper surface at the head end of the body with its central portion extending inwardly to a point adjacent the plane of the juncture between, the plug and head and'a convex lower surface at the plug end. and spaced from the plane of the juncture between the head and plug and the cylindrical plug having an outside diameter greater than the inside diameter of the opening in the container in which it is inserted so that the plug and diaphragm are partially compressed when inserted therein, asid plug having a circumferential groove extending completely around its outer surface immediately adjacent the head so as to relieve stresses of the plug resulting from resistance of said head-portion to compression of the plug and with the major portion of the diaphragm being positioned Within the plug so that when the plug is circumferentially compressed the elastomeric material in the diaphragm will flow inwardly in the direction of its convex surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,836,320 Carroll May 27, 1958 2,923,427 Klopfenstein a Feb. 2, 1960 F REIGNPATENTS 552,472 Italy Dec. 3, 1956 

